ES and SD?

[CM1021]

I have been reloading foe about two years now and enjoy it as much as shooting. Today I was trying to find a 175gr SMK load foe my .308 and the best group at 200 yards had the highest extreme spread and hughest standard deviation. From all my research I have heard that the most accurate load should have the lowest ES and SD. This load is very accurate at 200 yards but an ES of 37 and a SD of like 25. Plus its only running 2560 FPS or so. Don't have exacts as my data isn't here. I hot another load that's probably around an inch and a half with the ES of 8 and a SD of 4 or so. What says you guys.

[Guest Cazador]

how many shots in your group. If you are using only 3 shot group it is not enough to tell much. Your low es and sd group is still sub moa. I would load 10 of them and 10 of the smallest group and I would place a small wager that the lower es /sd group will be better.

[Luke E.]

 As mentioned above, you need to be shooting at least 5 shot groups when testing IMO. 

 

When comparing the tighter groups to the larger groups, were the larger groups opening up left to right or up and down? (I guess both is an acceptable answer as well)

 

ED and SD can effect windage but for the most part deviation effects elevation. Reason being that when one round carries a higher velocity it won't drop as much at a given range as a lower velocity round.